Luna-9

Today's trivia hopes to cover a slightly less well known Moon landing; from the Soviet Union space program.

The year is 1966, the Soviet Union had had mixed success with landings on the Moon. Since the start of their mission to land on the Moon in 1958, they had launched 20 missions. Only two missions, both in 1959, had succeeded. Luna-2 successfully (intentionally) crashed into the surface of the Moon, Luna-3 provided the first photos of the far side of the Moon.

However they were learning hugely from their space program and had refined the launch vehicle which would take the next mission, Luna-9 to the first soft body landing on the Moon.

Launch and Approach

The launch vehicle was the Molniya-M (a design derived from an earlier ICBM design, last used 2010) which operated as a four stage rocket. Was considerably more reliable than previous rockets and provided enough lift to get the 1.5 ton lander into orbit, set it into a gentle spin and provide the final velocity to get it into a trajectory towards the Moon.

A helpful simulation of the entire launch, approach and landing

This journey lasted 4 days and included a crucial course correction where the lander pivoted over so its rockets were directed at the Moon which allowed it to start its descent towards the surface.

The Luna-9 Lander; the body contained the flight control systems, the front contained the probe payload to deploy to the lunar surface

The lander was equipped with radar altimeter which allowed it to determine how high it was from the surface:

• At 25km from the surface the retro-rockets fired to slow descent
• At 250 meters the retro-rocket cut out and 4 stabilising rockets fired
• At 5 meters a contact sensor fires, and the probe is jettisoned from the top

The probe then bounced on an inflated air cushion before coming to rest on the lunar surface. Once stationary, the air cushion is jettisoned off.

A reconstruction of lander deployed the probe safely to the surface

The probe itself as comparatively quite simple. It consisted of a hermetically sealed container in which was held:

• radio equipment
• program timer
• heat control system
• geiger counter
• television system

Images Received

Approximately 250 seconds after the probe came to a halt the probe sprang open its four petal shaped panels and began a photographic survey of the lunar environment.

Model of the Luna-9 probe with 'petals' and radio masts deployed

The probe for the mission was equipped with a simple imaging system (by modern standards). It consisted of a television camera which pointed upwards and a mirror which was angled out towards the lunar surface. The mirror was rotated by a motor at a constant rate.

It would start recording images and broadcasting them via radio transmission back to Earth to be received by Soviet Union radio telescopes.

This also allowed the Jodrell Bank Lovell radio telescope to receive the same images.

Lovell Radio Telescope

It was quickly realised that the received signals were encoded in Radiofax, an internationally agreed standard for sending images between newspaper companies around the world.

"A Muirhead facsimile convertor and receiver were rushed out to Jodrell Bank from the Daily Express newspaper offices in Manchester. When the signals received the next afternoon were played through the machine, out scrolled, line by line, the first ever picture of the lunar surface taken from the surface." -- quote Professor Tim O'Brien

Perhaps to the Soviets dismay, the Express published the first image ever taken from the surface of the Moon before they did.

First photograph taken from the surface of the Moon in February 1966 by the Soviet lander Luna-9

Successes

The mission achieved a number of firsts:

• First soft body landing demonstrating the kind of flight control systems which would be required to land people on the Moon
• First images transmitted from the surface of another body in space
• Confirmation that the Moon's surface could support a foreign object; theories at the time predicted things might simply sink into the surface
• First recordings of radiation from the surface of the Moon (30 millirads per day)

A panoramic image captured by the probe full Size.

Last contact with the spacecraft was at 22:55 UT on 6 February 1966, after which its onboard batteries expired.